Method of manufacturing nozzle diaphragms and the like



Oct. 24, 1933. H. A. LACEY 1,932,273

METHOD OF MANUFACTURING NOZZLE DIAPHRAGMS. AND THE LIKE FiIed March 25,1932 Herr 1 A. Lacgg,

Hi s Attorngg.

Patented on. 24, 1933 UNITED STATES PATENT OFFICE,

METHOD OF MANUFACTURING NOZZLE DIAPHBAGMS, AND THE'LIKE Harry A. Lacey,Schenectady, N. Y., assignol to" General Electric Company, a corporationof New York Application March 25, 1932. Serial a 601,176

3 Claims. (Cl.29--156.8)

The present invention relates to the method of manufacturing nozzlediaphragms andthe like,

that is, structures or articles comprising a plu-' improvement over themethod disclosed in the copending application of E. D. Dickinson, SerialNo. 601,182, filed March 25, 1932.

The object of my invention is to provide an improved method for themanufacture of turbine diaphragms and like structures whereby themanufacturing cost is reduced.

For a consideration of what I believe to be go novel and my invention,attention is directed to the following description and the claimsappended thereto.

, In the drawing, Fig. 1 illustrates by way of example anozzle diaphragmin combination with 25 the shaft and the outer casing'of an elasticfluid turbine; Fig. 2 represents a portion of the nozzle diaphragmenlarged and embodying my invention; Figs. 3 to 6 inclusive showdifferent steps in the manufacture of nozzle diaphragmsemao-bodying myinvention and Figs. 7 to illustrate consecutive steps of a modifiedmethod embodying my invention: Figs. 4, 5, 8 and 9 show the nozzles insection, and Figs. '6' and 10 are top views of ..aj nczzle structure. InFig.1,where I have shown an application of my improved structure incombination with a diaphragm for an elastic fluid turbine, 1 representsa rotary turbine shaft, 2 indicates an annular disk to which is welded astructure 3 embodyand securely fastened thereto. 7 is a ring member heldin position in a groove 8 of the outer turbine casing 9. Structure 3comprising elements 4, 5 and 61s welded on one side to disk 2as-indicatedat 10 and on the other side to fio'ring member 7 asindicated at 11. It is-well known to those-skilled in the art thatblades 6 and rings 4 and 5 define nozzles and .serve for conveying astream of elastic fluid passed through a turbine from one stage to thesucceeding stage.

In Fig. 2, where I have shown a perspective ing 'my' invention. Thisstructure comprises stance are located near one'end of the holes.

view of my structure, 4 is the inner band which may be of any desiredform, straight or curved as in case of a turbine, 5 is the outer band ofthe same shape as band 4. Each band is provided with a plurality ofopenings or holes 14. 6 designates theblades or partitions; each bladeor partition having its ends projecting into corresponding holes 14 ofbands 4 and 5 respectively.

Before considering the present invention more specifically, attentionisdirected to the particular form or shape of blades or partitions as areused, in diaphragm structures and the like. Referring to Fig. 4, where Ihave shown a plurality of blades I 6 in cross section, each bladecomprises a cornparatively wide head portion Hand 9. narrow, taperedtail portion 17. i

v In carrying out one step of my invention I provide bands, strips orrings of metal within their confines with aplurality of holes by apunching process. As it would be difficult to punch holes of the sameshape as those of the blades, that is, with a comparatively thin,tapered'tail portion, I form these holes according to the method of myinvention with tail portions 19 (Fig. 3) which are wider than thecorresponding tail portions of the blades. The head portions 20 of theholes have, according to my invention, substantially the same' shape andsize as the head portions 16 of the blades.

For assembling the blades or partitions and the inner and outer band orring I arrange the bands or rings in spaced relation,asshown in Fig. '2,and

hold them in this relation by any suitable means,

not shown. The blades or partitions are then assembled by inserting themlengthwise through the holes of one band until the inserted end of withthe blades inserted. The arrangement is such that tail portions 17 ofthe blades and those of the holes define clearances 22. In ordertoeliminatethese clearances I provide saw-cuts 23 through the edges of thebands near the thin portion of the blades which in the present in- A.further step, according to my invention, is shown in Fig. 5 according towhich the edge portions defined adjacent the cuts are forced inwardly toengage or abut the side walls of the blades. To

'each blade projects into a corresponding hole of provide a straightedge of the band I remove, preferably by turning portions 24 below thedotted lines A--B in Fig. 5. v

Fig. 6 represents a top view of a structure after the turning operation.The blades and bands may be welded together as indicated at 25 in Fig.6.

It will be noted in connection with Fig. 4 that in the case of themanufacturing of a turbine diaphragm a great number of saw-cuts of theorder of 100 have to be made. The step of providing these saw-cuts iseliminated, or at least wards the edge 29 of the band. This extensionwhich serves to eliminate the saw-cuts 23 may be termed a cut portion;With bands thus provided with holes as shown in Fig. 'l I arrange twobands in spaced relation and insert the blades as described above.

- Fig. 8 shows a top view of a band with blades 30 inserted. Whereaswith the method above described it was necessary to provide a pluralityof saw-cuts, with the modified method according to my invention it isonly necessary to turn off the edge portion 31 below line C-D of Fig. 8whereby the extending hole portions 33 define open cuts. Thereafter edgeportions 32 can be forced towards the side walls of the blades as shownin Fig. 9. After this operation portions 34 of the edge are removed,along line E-F, preferably by turning, to provide a straight, smoothsurface, as shown in Fig. 10. The blades or partitions thereafter arewelded tothe band and the remaining cuts may also be filled with weldingmaterial as indicated at 35 in Fig. 10.

Whereas according to the method of the above mentioned copendingapplication a part only of the end portions of the partitions isinserted in the holes of a band, I insert according to my invention theentire end portions of the partitions in the holes of the bands.Furthermore, whereas in the copending application the partitions arewelded at one end to a disk and provided at their other ends only with aband, I provide such band for both ends of the partitions. This permitsan easyassembly of the nozzle structure for the diaphragm.

With my invention I have accomplished a simple and rigid structure whichis particularly suited for nozzle diaphragms of elastic fluid turbines.The partitions for blades used in my According to the modification of myinstructure are of standard form. The provision of an inner and an outershroud ring permits the manufacture of the nozzle structure as aseparate unit. This may be accomplished as indicated above by providingtwo concentric rings and preferably inserting the partitions through theouter ring so that each partition has its entire end portions projectinginto corresponding holes formed in the inner and outer ringrespectively. No spacing members for the partitions are necessary withmy invention as the correct relation of the partitions is determined bythe holes in the shroud rings.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. Method of manufacturing a structure comprising an outer and an innerband and a plurality of partitions, said method including punching holeswithin the confines of the bands such that each hole has a portionfitting a corresponding portion of a partition and another portion widerthan another corresponding portion of a partition, inserting the entireend portions of each partition lengthwise into corresponding holes inthe bands and eliminating the clearances defined between eachpartition-and an edge of each band. I I 2. Method of manufacturing astructure comprising an outer and an inner. band and a plurality ofpartitions, said method including forming holes in the bands such thateach hole has a portion fitting a corresponding portion of a partitionand another portion wider than an other corresponding portion of apartition, inserting the entire end portions of each partition intocorresponding holes in-the bands, cutting one edge of each band near thethin portion of each partition, forcing at least one edge portionadjacent each out against the'thin portion of the correspondingpartition, removing a part of the cut edge portion of each band andintegrallyuniting the bands and the partitions.

3. Method of manufacturing a structurecomprising an outer and an innerband and a plurality of partitions, said method comprising punchingholes within the confines of the bands, each hole having an extensiontowards one edge of the corresponding band and another portion widerthan a corresponding portion of a partition, assembling, the partitionsand the bands, removing a portionof one edge of each band so that theextending hole portions define open cuts, forcing the edge portionsadjacentthe cuts inwardly to abut theside's of the correspondingpartitions and welding the partitions to thebands. I I

' HARRY A. LACEY.

